Adding logs for easier debugging (#615)

src/main/java/com/microsoft/azure/functions/worker/Util.java

@@ -7,4 +7,8 @@ public class Util {
         }
         return false;
     }
+
+    public static String getJavaVersion() {
+        return String.join(" - ", System.getProperty("java.home"), System.getProperty("java.version"));
+    }
 }

src/main/java/com/microsoft/azure/functions/worker/handler/FunctionEnvironmentReloadRequestHandler.java

@@ -25,6 +25,7 @@ public class FunctionEnvironmentReloadRequestHandler
 
 	@Override
 	String execute(FunctionEnvironmentReloadRequest request, Builder response) throws Exception {
+		WorkerLogManager.getSystemLogger().log(Level.INFO, "FunctionEnvironmentReloadRequest received by the Java worker");
 		EnvironmentVariables = request.getEnvironmentVariablesMap();
 		if (EnvironmentVariables == null || EnvironmentVariables.isEmpty()) {
 			return String

src/main/java/com/microsoft/azure/functions/worker/handler/FunctionLoadRequestHandler.java

@@ -1,7 +1,9 @@
 package com.microsoft.azure.functions.worker.handler;
 
 import java.util.*;
+import java.util.logging.Level;
 
+import com.microsoft.azure.functions.worker.WorkerLogManager;
 import com.microsoft.azure.functions.worker.broker.*;
 import com.microsoft.azure.functions.worker.description.*;
 import com.microsoft.azure.functions.rpc.messages.*;
@@ -18,6 +20,7 @@ public class FunctionLoadRequestHandler extends MessageHandler<FunctionLoadReque
 
     @Override
     String execute(FunctionLoadRequest request, FunctionLoadResponse.Builder response) throws Exception {
+        WorkerLogManager.getSystemLogger().log(Level.INFO, "FunctionLoadRequest received by the Java worker");
         final RpcFunctionMetadata metadata = request.getMetadata();
         final FunctionMethodDescriptor descriptor = createFunctionDescriptor(request.getFunctionId(), metadata);
         

src/main/java/com/microsoft/azure/functions/worker/handler/InvocationRequestHandler.java

@@ -7,6 +7,8 @@ import com.microsoft.azure.functions.worker.*;
 import com.microsoft.azure.functions.worker.broker.*;
 import com.microsoft.azure.functions.rpc.messages.*;
 
+import static com.microsoft.azure.functions.worker.Util.getJavaVersion;
+
 public class InvocationRequestHandler extends MessageHandler<InvocationRequest, InvocationResponse.Builder> {
     public InvocationRequestHandler(JavaFunctionBroker broker) {
         super(StreamingMessage::getInvocationRequest,
@@ -23,6 +25,8 @@ public class InvocationRequestHandler extends MessageHandler<InvocationRequest,
 
     @Override
     String execute(InvocationRequest request, InvocationResponse.Builder response) throws Exception {
+        WorkerLogManager.getSystemLogger().log(Level.INFO, "Java version - " + getJavaVersion());
+        WorkerLogManager.getSystemLogger().log(Level.INFO, "InvocationRequest received by the Java worker");
         final String functionId = request.getFunctionId();
         final String invocationId = request.getInvocationId();
 

src/main/java/com/microsoft/azure/functions/worker/handler/WorkerInitRequestHandler.java

@@ -4,6 +4,8 @@ import com.microsoft.azure.functions.worker.*;
 import com.microsoft.azure.functions.rpc.messages.*;
 import com.microsoft.azure.functions.worker.broker.JavaFunctionBroker;
 
+import java.util.logging.Level;
+
 public class WorkerInitRequestHandler extends MessageHandler<WorkerInitRequest, WorkerInitResponse.Builder> {
     public WorkerInitRequestHandler(JavaFunctionBroker broker) {
         super(StreamingMessage::getWorkerInitRequest,
@@ -15,6 +17,7 @@ public class WorkerInitRequestHandler extends MessageHandler<WorkerInitRequest,
 
     @Override
     String execute(WorkerInitRequest request, WorkerInitResponse.Builder response) {
+        WorkerLogManager.getSystemLogger().log(Level.INFO, "WorkerInitRequest received by the Java worker");
         broker.setWorkerDirectory(request.getWorkerDirectory());
         response.setWorkerVersion(Application.version());
         response.putCapabilities("TypedDataCollection", "TypedDataCollection");